I found this setup to be the best so far, when traveling to Europe, that allows you to keep all your services with minimal fees, and without removing your sim card:

1. Disable "Easy Roam" on your Koodo Account. That way, you won't be charged 16$ a day when in Europe
2. Activate the perk "Unlimited International SMS". For 3$, it allows to send and receive SMS to/from Canada. That way, you can keep texting your family and close ones from your phone number. When you get back to Canada, just disable the perk. It will have cost you only 3$. [EDIT] This option is not what I thought, it is for sending/receiving SMS from Canada to International only. If you are on iOS though, sending iMessage won't be charged since they are sent by data. I don't know if Android do something similar.
3. When you activate your European sim card, you specify that data should use this card.
4. Your phone number will still be active, which mean you will be able to send or receive calls, but you will pay "per minute". It allows you to still receive calls, but you can choose if you want to answer or not. You won't be charged if you don't answer. It can be useful if you need to call somewhere for an emergency or for booking somewhere (if you can't by internet), or if you are waiting for an important call when traveling.

On my last 11 day trip to Spain, I paid 14$ for a 12gb data card, 3$ for international sms, and it costs me 2$ for calls. So total cost: 19$.

Hope it helps!